Metallic tube



(No Model.)

C. L. BETTS. METALLIC TUBE.

No. 425,975. Patented Apr.'ZZ 1890.

Wines-sea jarlesl Zeiis .Zrv 7oz q: .7

UNITE STATES PATENT OFFIcE.

CHARLES L. BETTS, OF NEW YORK, N. Y., ASSIGNOR TO THE R. E. DIETZ COMPANY, OF SAME PLACE, AND THE STEAM GAUGE AND LANTERN COMPANY, OF SYRACUSE, NEYV YORK.

METALLIC TUBE.

SPECIFICATION forming part of Letters Patent No. 425,975, dated April 22, 1890.

Application filed December 30, 1889. Serial No.335,804. (No model.)

To all whom it may concern:

Be it known that I, CHARLES L. BETTS, a citizen of the United States, residing at New York,-in the county and State of New York,

have invented a new and useful Improvement in Metallic Tubes, of which the following is a specification.

This invention relates to that class of me tallic tubes which are made of thin sheet metal-for instance, tinand its principal object is to produce a tube which has the longitudinal edges of its blank securely locked together in a simple and inexpensive manner.

In the accompanying drawings, Figure 1 is r 5 an elevation of a tubular lantern provided with my improved tube. Fig. 2 is a view of the blank from which the tube is bent. Fig. 3 represents the blank bent preparatory to interlocking its longitudinal edges. Fig. 4:

represents the tube with its longitudinal edges interlocked. Fig. 5 is a horizontal section in line 03 00, Fig. 1, 011 an enlarged scale.

Like letters of reference refer to like parts in the several figures.

A represents the blank from which the tube is bent, and l) and 0 represent the longitudinal edges of the blank. The blank is provided near the edge I) with longitudinal slits cl and on the longitudinal edge c with 0 projecting lips E. The latter project beyond the edge of the blank and the overhanging or undercut rounded end of each lip projects longitudinally beyond the end of the corresponding slit (1, as represented in Fig. 3, so

3 5 that the lips cannot be inserted into the slits except upon slightly twisting the blank lengthwise. into the slits, when the blank is released and the longitudinal edges resume their normal position lengthwise and securely locks the edges together. The marginal portion of the blank from the slits to the edge Z) is preferably depressed, as represented in Fig. 5, so that the slits are located in the shoulder e011- 4 5 necting the depressed marginal portion with the main portion of the blank, and face the edges of the lips, whereby the insertion of the lips into the slits is facilitated. The lips E are constructed with inclined or oblique 5o backs, which come in contact with the adjacent ends of the slits in insertingthe lips and cause or assist in causing the longitudinal movement of one edge with reference to the This causes the lips to hook other in the proper direction to lock the lips in the slits.

In the lantern represented in Fig. 1 my improved construction of a tube is employed in the central tube F, which connects the bell G of a well-known tubular lantern with the upper ends of the side tubes H H, and also in 6c the air-chamber I, with which the lower ends of the side tubes connect. In both the central tube F and the chamber Ithe connection of the tube with the cylindrical wall of the tube or air-chamber is strengthened and facilitated by cars and Z, which are formed, respectively, on the tube and air-chamber, and which bear against the sides of the side tubes. Vhen this central tube F and the airchamber are secured in the lantern,the parts 70 with which they are connected prevent the lips from becoming unhooked from the slits. Tubes of this construction when made of tin are much stronger than soldered tubes and less expensive, because they effect a large saving in solder.

My improved construction of a tube is particularly desirable in lanterns and similar structures, but may be advantageously employed for stove-pipes and other tubes.

I claim as my invention- 1. A sheet-metal tube having one of its longitudinal edges provided with longitudinal slits and the other edge with undercut lips adapted to be hooked into the slits by a longitudinal movement of one edge of the blank with reference to the other, substantially as set forth.

2. A sheet-metal tube having one of its longitudinal edges provided with longitudio nal slits and the other with undercut lips having inclined backs, substantially as set forth.

3. A sheet-metal tube having its longitudinal edges provided with interlocking slits and lips, and having openings in its cylindrical wall, and projecting lips 011 opposite sides of said openings, substantially as set forth.

Vitness my hand this 23d dayof Decem- 10o ber, 1889.

CHARLES L. BETTS.

Witnesses:

I. J. ALLEN, JOHN E. Drnrz. 

